230 research outputs found
Symmetry Classes of Spin and Orbital Ordered States in a t_{2g} Hubbard Model on a Two-dimensional Square Lattice
This paper presents symmetry classes of the Hartree-Fock (HF) solutions of
spin and orbital ordered states in a t_{2g} Hubbard model on a two-dimensional
square lattice. Using a group theoretical bifurcation theory of the Hartree
Fock equation, we obtained many types of broken symmetry solutions which
bifurcate from the normal state through one step transition in cases of
commensurate ordering vectors Q_0=(0,0), Q_1=(\pi,\pi), Q_2=(\pi,0) and
Q_3=(0,\pi). Each broken symmetry state is characterized by the presence of
local order parameters(LOP) at each lattice site: quadrupole moment
Q=(Q_2^2,Q_{12},Q_{23},Q_{31}), orbital angular momentum l=(l_1,l_2,l_3), spin
density s=(s^1,s^2,s^3), spin quadrupole moment Q^{\lambda}=(Q_2^{2\lambda},
Q_{12}^{\lambda},Q_{23}^{\lambda},Q_{31}^{\lambda}) and spin orbital angular
momentum l^{\lambda}=(l_1^{\lambda},l_2^{\lambda},l_3^{\lambda}) where
\lambda=1,2,3. We performed numerical calculations for some parameter sets.
Then we have found that many types of non-collinear magnetic orbital ordered
states having LOP:Q^{\lambda} and l^{\lambda} can be the ground state for these
parameter sets.Comment: 46 pages with 4 figure
Carbon Nanoarch Encapsulating Fe Nanowire on Ni (111)
We investigate the stable structures of Fe-filled single-walled carbon
nanotubes (SWNTs) on Ni(111), using density functional theory calculations. We
find stable geometries and electronic states for the nanotube on Ni(111). We
propose the possibility that the C-C bonds of carbon nanotube are broken by Fe
wire and Ni surface. That is, when Fe-filled SWNT(3, 3) adsorb on Ni(111)
surface, SWNT transforms into arch-like structure.Comment: 13 pages, 6 figures, submitted to Japanese Journal of Applied Physics
22 April 2005. submitted to Japanese Journal of Applied Physics 22 April 200
Intraoperative electrocorticography and successful focus resection in a case of Sturge-Weber syndrome
This paper reports a surgically treated case of Sturge-Weber syndrome (SWS) in which the epileptic foci and haemangiomatosis were successfully resected under monitoring of intraoperative electrocorticography. The patient was a 19-month-old female infant who was referred to our hospital because of frequent hemi-tonic-clonic convulsions that were resistant to anticonvulsant therapy. Serial MRI showed progressive atrophy in the left fronto-parieto-temporal lobe, and gyral enhancement by gadolinium corresponded to venous haemangiomatosis of SWS. Three-dimensional reconstruction of the MR images was performed using the Viewing Wand System. Conventional EEG taken before the operation showed slow activity in the left frontal lobe. Intraoperative ECoG revealed spike focus at the posterior temporal cortex to the margin of the haemangiomatosis. Lesionectomy with lobar corticectomy of the total frontal and parietal lobe and part of the temporal lobe was performed. The epileptogenic focus detected by ECoG in the posterior temporal lobe was also resected. In post-excisional ECoG, epileptogenic activities had disappeared. The patient had hemiparesis and hemihypesthesia just after the surgery, but gradually recovered from the paresis and almost has normal motor function except for right-hand clumsiness up to 1 year after surgery. The present study demonstrated that lobar corticectomy of the haemangiomatosis-affected cortex with resection of the neighbouring epileptogenic focus is a good surgical alternative even if a haemangiomatosis of the SWS affected multilobar corti of the hemisphere
Inadvertent Ingestion of a Press-Through Package Causing Perforation of the Small Intestine within an Incisional Hernia and Panperitonitis
A 90-year-old woman was admitted to the emergency department of our hospital with abdominal pain and a fever of up to 39°C. She had a history of hysterectomy about 30 years previously, and redness and swelling were seen at the abdominal median scar. Serum biochemistry showed minor elevation of C-reactive protein and creatine phosphokinase. Abdominal computed tomography (CT) showed an edematous intestinal tract image over the median abdominal wall. Incarcerated incisional hernia and intestinal necrosis were suspected. Therefore, emergency surgery was performed. On laparotomy, abundant purulent ascitic fluid was found. The small intestine was incarcerated about 100 cm orally from the terminal ileum, and a 2-mm perforation was present in the incarcerated small intestine. In addition, some white areas measuring 1 mm were found in the small intestinal wall. A press-through package (PTP) of a tablet was confirmed in the intestinal tract near the perforated area. We removed the PTP through the perforation and performed direct suture. Postoperatively, we retrospectively reviewed the CT image and found a high-density shadow which seemed to represent the PTP
Small airway disease associated with Sjögren’s syndrome: Clinico-pathological correlations
SummaryBackgroundRelationships among clinical, physiological, imaging and pathological findings of small airway disease associated with Sjögren’s syndrome have remained unclear.Subjects and methods: We retrospectively studied 14 patients who underwent surgical lung biopsy and who were diagnosed with small airway disease associated with primary or secondary Sjögren’s syndrome. We compared clinical, bronchoalveolar lavage, physiological, imaging and pathological findings between primary and secondary Sjögren’s syndrome. We scored HRCT and pathological abnormalities and investigated correlations among physiological, HRCT and pathological data, changes in physiological parameters and in HRCT scores after two years of treatment, as well as correlations between these values and pathological scores.ResultsBronchoalveolar lavage fluid, physiological, imaging and pathological findings of the airways did not significantly differ between primary and secondary Sjögren’s syndrome. Air trapping on HRCT negatively correlated with MEF50 and MEF25. Although lymphoid cell infiltration and peribronchiolar fibrosis were the most common pathologies, constrictive change scores correlated negatively with MEF50 and MEF25, positively with air trapping scores and negatively with improvements after therapy in MEF50, MEF25 and air trapping.ConclusionsConstrictive change was the most significant determinant of physiological and imaging presentations and of changes in these factors after therapy for small airway disease associated with Sjögren’s syndrome
Three Japanese patients with congenital pituitary hormone deficiency and ophthalmological anomalies
The clinical phenotype of congenital pituitary hormone deficiency is variable and can be associated with a number of structural abnormalities of the central nervous system. We report three Japanese patients with congenital pituitary hormone deficiency and ophthalmological anomalies. Two of the patients initially showed strabismus and unilateral optic nerve hypoplasia. Thereafter, growth failure became evident, leading to the diagnosis of pituitary hormone deficiency. The other patient had severe congenital hypopituitarism with respiratory distress and hypoglycemia from the first day of life. In addition, he had prolonged jaundice and impaired liver function with bilateral optic nerve hypoplasia. Neuroimaging of the pituitary region in all three patients demonstrated a small anterior pituitary lobe and no pituitary stalk. Our findings indicate that clinical variability of congenital hypopituitarism must be considered. In a patient with ophthalmological symptoms, endocrine evaluation and neuroimaging of the CNS including the pituitary region should be considered
Dusty ERO Search behind Two Massive Clusters
We performed deep K'-band imaging observations of 2 massive clusters, MS
0451.6-0305 at z = 0.55 and MS 0440.5+0204 at z = 0.19, for searching
counterparts of the faint sub-mm sources behind these clusters, which would
provide one of the deepest extremely red object(ERO) samples. Comparing our
near-infrared images with optical images taken by the Hubble Space Telescope
and by the Subaru Telescope, we identified 13 EROs in these fields. The sky
distributions of EROs are consistent with the previous results, that there is a
sign of strong clustering among detected EROs. Also, the surface density with
corrected lensing amplification factors in both clusters are in good agreement
with that derived from previous surveys. We found 7 EROs and 3 additional very
red objects in a small area (\sim 0.6 arcmin^2) of the MS 0451.6-0305 field
around an extended SCUBA source. Many of their optical and near-infrared colors
are consistent with dusty star-forming galaxies at high redshifts(z \sim
1.0-4.0), and they may be constituting a cluster of dusty starburst galaxies
and/or lensed star-forming galaxies at high redshift. Their red J-K' colors and
faint optical magnitudes suggest they are relatively old massive stellar
systems with ages(>300 Mega years) suffering from dust obscuration. We also
found a surface-density enhancement of EROs around the SCUBA source in the MS
0440.5+0204 field.Comment: 19 pages, 11 figures, Latex(using pasj00.cls). To be published in
PASJ vol 55, No. 4(Aug 2003
Long-Term Survival of Resected Advanced Gastric Cancer with Hepatic and Pancreatic Invasion
A 64-year-old man was transferred to our division with a suspicion of gastric cancer. Computed tomography showed widespread irregular thickening of the stomach walls close to the liver and pancreas. Gastrointestinal fiberscopy showed a type 5 tumor in the upper to lower stomach, histologically diagnosed as tubular adenocarcinoma. Gastric cancer with hepatic and pancreatic invasion was diagnosed. Distant metastasis was not proven and complete resection was planned. At laparotomy, the tumor showed general expanding growth and invasion through the lateral segment of the liver and pancreas. Total gastrectomy and combined resection of the distal pancreas, spleen and left segment of the liver were performed. Hepatic and pancreatic invasion and lymph node metastasis were microscopically proven. Pancreatic fistula occurred postoperatively. On postoperative days 40, he was discharged. He received two cycles of adjuvant tegafur/gimeracil/oteracil chemotherapy. He has had no sign of recurrence for 7 years and 8 months
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